[osis-core] scripCom

[Harry Plantinga]

ThML has a <scripCom type="sermon" passage="Rev. 1:1-3"/> 
element which basically says "this is a commentary of type 
sermon on Revelation 1:1-3." Can that be said in OSIS?

This doesn't quite capture it all:

<milestone type="commentary" work="bible" cite="Rev.1.1" 
outCite="Rev.1.3" />

Any other ideas?

-Harry